Several people have asked for copies of my IMPERFECTO RULER, seen in the Numberphile video "Secrets to measuring a piece of paper", at https://youtu.be/9yUZTTLpDtk
Here are downloadable copies of the THEOPHILUS MEASURE CO IMPERFECTO RULER. (above is for US Letter paper, below is scaled for the rest of the universe)
I printed these onto stiff white paper; 0.25mm thick; this is called "65 pound basis weight" in the USA. A "straight through" printer works best (my Epson inkjet printer has a rear-feed for just this purpose)
Likely, you will have to adjust your computer printer's scale factor to get the ruler to be just the right length. Not that this makes any difference!
I trim the ruler to size using a paper cutter. You can use a scissors, but for making twenty or thirty rulers, a rotary paper cutter or guillotine paper slicer works nicely.
You can help support further development of additionalimperfecto devices by purchasing an Acme Klein Bottle. Enjoy! -Cliff
The Imperfecto Ruler
Theophilus Measure Co
Imperfect Ruler by Cliff Stoll
Uploaded Oct 2017